FIG. 1 is an illustration of selected components of a disk drive 10 according to the prior art. The disk drive includes at least one magnetic recording disk 12 that rotates on spindle 13 in direction 15 driven by a spindle motor (not shown). Housing or baseplate 16 provides support for the components. The upper portion of the outer protective case, which is present for normal operation, is removed for this illustration. The data is recorded concentric or spiral, generally circular data tracks 50, only a small portion of which are shown. In practice there are thousands of tracks that extend 360 degrees around the disk. The disk drive includes actuator 14 pivots on pivot point 17 driven by a rotary voice coil motor (VCM) (not shown). The actuator 14 includes a rigid actuator arm 18. A flexible wiring cable 24, which is usually called the “flex cable,” connects the devices on the actuator including read and write heads (not shown) in the slider 22 and the read/write integrated circuit chip (R/W IC) (not shown) to the drive's electronics (not shown). The R/W IC is typically mounted on the actuator arm or can be integrated into the flexible wiring cable, which is usually called the “flex cable.” A flexible suspension 20 includes a flexure element (not shown) and is attached to the end of arm 18. Air-bearing slider 22 contains the read/write heads (not shown). As the disk 12 rotates, the slider with read/write heads is positioned over a track to read and write the magnetic transitions. The read head also detects the angularly spaced servo sectors 60 in the data tracks. Only two of the many servo sectors 60 are shown for simplicity.
Disk drives often have more than one disk mounted on the spindle and the upper and lower surfaces of each disk can have magnetic recording material thereon, and the actuators with components mounted thereon are replicated as needed to access each of the recording surfaces.
The flex cable 24 provides electrical connections between the actuators and the drive electronics on a circuit board (not shown). The flex cable 24 is rigidly attached by stationary bracket 23 at one end, which connects to drive electronics. The other end of the flex cable is attached to the set of actuators 14 which move in unison in response to the VCM. In the example shown in FIG. 1, a stiffener 26A is illustrated as being part of the flex cable. The stiffener 26A, which is a thin layer of aluminum is bonded to one side the flex cable. Although only one stiffener segment is shown, another stiffener segment can be located close to the actuator as is shown in FIG. 2.
FIG. 2 is an illustration of a prior art flex cable 24 prior to being installed in a disk drive. The bracket end 24B is rigidly attached by stationary bracket 23 when installed. The trace pad area 25 provides the connections to drive electronics (not shown) for each of the plurality of embedded conductive traces 24T. Only two of the plurality of trace pads 24P are shown for simplicity. There are two stiffeners 26A, 26B in this example attached to the bottom surface of the flex cable. The stiffener 26B is located at the actuator connecter end 24A. FIG. 3 is an illustration of an section view taken along line A-A of the prior art flex cable shown in FIG. 2. A standard single-layer flex cable includes a set conductive traces 24T encapsulated inside flexible encapsulation material 24M, e.g. polyimide. The width and conducting capacity of the individual traces can vary according to requirements. The traces are typically made of copper.